Transmission mechanism, follow focus, follow focus actuator, and imaging device

ABSTRACT

A transmission mechanism includes an output member and a worm wheel shaft configured to be connected to a power device to transmit a power of the power device to the output member. The worm wheel shaft and the output member are engaged with each other through a relative movement along an axial direction. An engagement between the worm wheel shaft and the output member limits a relative rotation between the worm wheel shaft and the output member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 15/958,692,filed Apr. 20, 2018, which is a continuation of InternationalApplication No. PCT/CN2015/092466, filed on Oct. 21, 2015, the entirecontents of both of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a transmission mechanism, a followfocus, a follow focus actuator and an imaging device.

BACKGROUND OF THE DISCLOSURE

A follow focus can comprise a motor and an output gear coupled to themotor. The output gear can be sleeved on a rotating shaft of the motorand coupled to the rotating shaft by a fastening screw, such that atorque can be transmitted from the motor to the output gear through therotating shaft. An end of the fastening screw can pass through theoutput gear along a radial direction of the rotating shaft and can bethen mounted in the rotating shaft. An assembly and disassembly of thefollow focus can be inconvenient as specific tools are required.

SUMMARY OF THE DISCLOSURE

There is a need for a transmission mechanism, a follow focus, a followfocus actuator and an imaging device that can be conveniently assembledand disassembled.

An aspect of the present disclosure provides a transmission mechanismfor transmitting a power of a power device, the transmission mechanismcomprising an adaptor and an output member, the adaptor being connectedto the power device and transmitting the power of the power device tothe output member, the output member outputting the power, the adaptordriving a coaxial rotation of the output member by a rotation of theadaptor to output the power. The adaptor and the output member can beengaged with each other through a relative movement along an axialdirection. The engagement can limit a relative rotation between theadaptor and the output member. The transmission mechanism can furthercomprise a locking member rotatably provided on the output member, thelocking member passing through the output member along an axialdirection of the output member and comprising an operating portion. Theoperating portion can be operable to connect the locking member with theadaptor or disconnect the locking member from the adaptor. The relativemovement between the adaptor and the output member along the axialdirection can be limited when the locking member are connected to theadaptor.

In some embodiments, the adaptor can comprise an engaging portion. Theoutput member can comprise a holding portion. The engaging portion canabut against the holding portion or release from the holding portion tobring the transmission mechanism into an assembled state or adisassembled state.

In some embodiments, the output member can comprise a holding member andan output gear connected to the holding member. The holding member canabut against the adaptor or release from the adaptor to bring thetransmission mechanism into the assembled state or the disassembledstate. The output member can output the power to a load through theoutput gear.

In some embodiments, the holding portion can be formed on the holdingmember.

In some embodiments, the engaging portion can comprise a plurality ofprotruding blocks, a slot being formed between two adjacent protrudingblocks. The holding portion can comprise a plurality of protrusionscorresponding to the slots. The protrusions can engage into or disengagefrom the corresponding slots to cause the engaging portion abut againstthe holding portion or release from the holding portion.

In some embodiments, the adaptor can comprise a transmission shaft. Theengaging portion can be provided at an end portion of the transmissionshaft. The plurality of protruding blocks can be arranged along acircumference of an end face of the transmission shaft with an intervaltherebetween.

In some embodiments, two engaging portions can be respectively providedat two ends of the transmission shaft.

In some embodiments, the adaptor can further comprise a transmissionwheel for connecting the power device. A mounting portion can be formedon the transmission shaft at which the transmission wheel can beprovided. The mounting portion can prevent a movement of thetransmission wheel relative to the transmission shaft along acircumferential direction and an axial direction of the transmissionshaft.

In some embodiments, four mounting portions can be evenly arranged alongthe circumferential direction of the transmission shaft.

In some embodiments, the transmission wheel can comprise a plurality ofgear teeth through which the transmission wheel can be meshed with thepower device.

In some embodiments, an angle between a lengthwise direction of the gearteeth and an axial direction of a central axis of the transmission wheelcan be an acute angle.

In some embodiments, the locking member can pass through the output gearand the holding member and be threadedly connected to or disconnectedfrom the adaptor to cause the holding member abut against the adaptor orrelease from the adaptor.

In some embodiments, the locking member can comprise a connecting rod,the connecting rod being threadedly connected to or disconnected fromthe transmission shaft to cause the holding member abut against theadaptor or release from the adaptor.

In some embodiments, the transmission shaft can be provided with anaccommodating hole. A collar can extend from a position at a middle ofan inner wall of the accommodating hole, and the adaptor can bethreadedly connected to or disconnected from the connecting rod throughthe collar.

In some embodiments, a thread can be formed on a surface of the collarfacing a central axis of the transmission shaft.

In some embodiments, the holding member can be provided with a via hole,and the output gear can be provided with a through hole and a groove incommunication with the through hole. The holding member can be mountedwithin the groove. The locking member can protrude from the holdingmember upon passing through the through hole and the via hole.

In some embodiments, the plurality of protrusions can be arranged alonga circumference of the via hole with an interval therebetween.

In some embodiments, the holding member can be provided with a guidehole. A rib can be fixed on a bottom surface of the groove facing theholding member. The rib can be inserted into the guide hole to guide aconnection between the output gear and the holding member.

In some embodiments, the output gear can comprise a meshing portionthrough which the output gear can drive a rotation of the load.

Another aspect of the present disclosure provides a follow focus, thefollow focus comprising a casing, a power device and a transmissionmechanism connected to the casing for transmitting a power of the powerdevice, the transmission mechanism comprising an adaptor and an outputmember, the adaptor being connected to the power device and transmittingthe power of the power device to the output member, the output memberoutputting the power, the adaptor driving a coaxial rotation of theoutput member by a rotation of the adaptor to output the power. Theadaptor and the output member can be engaged with each other through arelative movement along an axial direction. The engagement can limit arelative rotation between the adaptor and the output member. Thetransmission mechanism can further comprise a locking member rotatablyprovided on the output member, the locking member passing through theoutput member along an axial direction of the output member andcomprising an operating portion. The operating portion can be operableto connect the locking member with the adaptor or disconnect the lockingmember from the adaptor. The relative movement between the adaptor andthe output member along the axial direction can be limited when thelocking member are connected to the adaptor.

In some embodiments, the power device can be provided within the casing.The transmission mechanism can be provided on the casing through theadaptor. The transmission mechanism can be connected to the power devicethrough the adaptor. The power device can drive a rotation of the outputmember through the adaptor.

In some embodiments, a clearing slot can be provided on the casing foraccommodating the output member upon assembling the follow focus.

In some embodiments, two clearing slots can be provided facing away fromeach other.

In some embodiments, the casing can be provided with a housing hole incommunication with the clearing slot. The adaptor can be mounted withinthe housing hole.

In some embodiments, a receiving cavity in communication with thehousing hole can be formed in the casing. The power device can bereceived in the receiving cavity.

In some embodiments, the power device can comprise an output shaftmeshed with the adaptor to drive the rotation of the adaptor.

In some embodiments, the follow focus can further comprise a latchingmember connected to the casing. The follow focus can be detachablyconnected to a carrier through the latching member.

In some embodiments, the latching member can comprise a knob movablyconnected to the casing, a stationary portion connected to the casingand a movable portion rotatably connected to the stationary portion. Theknob can be rotatable relative to the casing to bring the latchingmember into a locked state or a disassembled state.

In some embodiments, the movable portion can be connected to the knob.The knob can drive a rotation of the movable portion relative to thestationary portion.

In some embodiments, a receiving hole for receiving the carrier can beformed by the movable portion and the stationary portion when thelatching member is in the locked state.

In some embodiments, the adaptor can comprise an engaging portion, andthe output member can comprise a holding portion. The engaging portioncan abut against the holding portion or release from the holding portionto bring the transmission mechanism into an assembled state or adisassembled state.

In some embodiments, the output member can comprise a holding member andan output gear connected to the holding member. The holding member canabut against the adaptor or release from the adaptor to bring thetransmission mechanism into the assembled state or the disassembledstate. The output member can output the power to a load through theoutput gear.

In some embodiments, the holding portion can be formed on the holdingmember.

In some embodiments, the engaging portion can comprise a plurality ofprotruding blocks, a slot being formed between two adjacent protrudingblocks. The holding portion can comprise a plurality of protrusionscorresponding to the slots. The protrusions can engage into or disengagefrom the corresponding slots to cause the engaging portion abut againstthe holding portion or release from the holding portion.

In some embodiments, the adaptor can comprise a transmission shaft. Theengaging portion can be provided at an end portion of the transmissionshaft. The plurality of protruding blocks can be arranged along acircumference of an end face of the transmission shaft with an intervaltherebetween.

In some embodiments, two engaging portions can be respectively providedat two ends of the transmission shaft.

In some embodiments, the adaptor can further comprise a transmissionwheel for connecting the power device. A mounting portion can be formedon the transmission shaft at which the transmission wheel can beprovided. The mounting portion can prevent a movement of thetransmission wheel relative to the transmission shaft along acircumferential direction and an axial direction of the transmissionshaft.

In some embodiments, four mounting portions can be evenly arranged alongthe circumferential direction of the transmission shaft.

In some embodiments, the transmission wheel can comprise a plurality ofgear teeth through which the transmission wheel can be meshed with thepower device.

In some embodiments, an angle between a lengthwise direction of the gearteeth and an axial direction of a central axis of the transmission wheelcan be an acute angle.

In some embodiments, the locking member can pass through the output gearand the holding member and be threadedly connected to or disconnectedfrom the adaptor to cause the holding member abut against the adaptor orrelease from the adaptor.

In some embodiments, the locking member can comprise a connecting rod,the connecting rod being threadedly connected to or disconnected fromthe transmission shaft to cause the holding member abut against theadaptor or release from the adaptor.

In some embodiments, the transmission shaft can be provided with anaccommodating hole. A collar can extend from a position at a middle ofan inner wall of the accommodating hole. The adaptor can be threadedlyconnected to or disconnected from the connecting rod through the collar.

In some embodiments, a thread can be formed on a surface of the collarfacing a central axis of the transmission shaft.

In some embodiments, the holding member can be provided with a via hole,and the output gear can be provided with a through hole and a groove incommunication with the through hole. The holding member can be mountedwithin the groove. The locking member can protrude from the holdingmember upon passing through the through hole and the via hole.

In some embodiments, the plurality of protrusions can be arranged alonga circumference of the via hole.

In some embodiments, the holding member can be provided with a guidehole. A rib can be fixed on a bottom surface of the groove facing theholding member. The rib can be inserted into the guide hole to guide aconnection between the output gear and the holding member.

In some embodiments, the output gear can comprise a meshing portionthrough which the output gear can drive a rotation of the load.

In some embodiments, two output members can be provided each of whichbeing detachably connected to the adaptor through the locking member.The adaptor can drive a coaxial rotation of the two output members.

Another aspect of the present disclosure provides an imaging device, theimaging device comprising a gimbal, an imaging element provided on thegimbal and a follow focus provided on the gimbal, the follow focuscomprising a casing, a power device and a transmission mechanismconnected to the casing for transmitting a power of the power device,the transmission mechanism comprising an adaptor and an output member,the adaptor being connected to the power device and transmitting thepower of the power device to the output member, the output memberoutputting the power to the imaging element, the adaptor driving acoaxial rotation of the output member by a rotation of the adaptor tooutput the power. The adaptor and the output member can be engaged witheach other through a relative movement along an axial direction. Theengagement can limit a relative rotation between the adaptor and theoutput member. The transmission mechanism can further comprise a lockingmember rotatably provided on the output member, the locking memberpassing through the output member along an axial direction of the outputmember and comprising an operating portion. The operating portion can beoperable to connect the locking member with the adaptor or disconnectthe locking member from the adaptor. The relative movement between theadaptor and the output member along the axial direction can be limitedwhen the locking member are connected to the adaptor.

In some embodiments, the gimbal can comprise a carrier, a carryingplatform and a mounting rod provided on the carrier, a first operatinghandle and a second operating handle connected to the mounting rod, anda carrying rod connected to the carrying platform. The imaging elementcan be provided on the carrying platform. The follow focus can beconnected to the carrying rod.

In some embodiments, the follow focus can comprise a gear ring. The gearring can be sleeved on a lens ring of the imaging element. The gear ringcan be meshed with the output member. The power device can drive arotation of the gear ring through the adaptor to effect a focusing ofthe imaging element. Or the gear ring can be sleeved on an aperture ringof the imaging element and meshed with the output member. The powerdevice can drive a rotation of the gear ring through the adaptor toeffect an aperture adjustment of the imaging element.

In some embodiments, the power device can be provided within the casing.The transmission mechanism can be provided on the casing through theadaptor. The transmission mechanism can be connected to the power devicethrough the adaptor. The power device can drive a rotation of the outputmember through the adaptor.

In some embodiments, a clearing slot can be provided on the casing foraccommodating the output member upon assembling the follow focus.

In some embodiments, two clearing slots can be provided facing away fromeach other.

In some embodiments, the casing can be provided with a housing hole incommunication with the clearing slot. The adaptor can be mounted withinthe housing hole.

In some embodiments, a receiving cavity in communication with thehousing hole can be formed in the casing. The power device can bereceived in the receiving cavity.

In some embodiments, the power device can comprise an output shaftmeshed with the adaptor to drive the rotation of the adaptor.

In some embodiments, the follow focus can further comprise a latchingmember connected to the casing. The follow focus can be detachablyconnected to the gimbal through the latching member.

In some embodiments, the latching member can comprise a knob movablyconnected to the casing, a stationary portion connected to the casingand a movable portion rotatably connected to the stationary portion. Theknob can be rotatable relative to the casing to bring the latchingmember into a locked state or a disassembled state.

In some embodiments, the movable portion can be connected to the knob.The knob can drive a rotation of the movable portion relative to thestationary portion.

In some embodiments, a receiving hole for receiving the carrier can beformed by the movable portion and the stationary portion when thelatching member is in the locked state.

In some embodiments, the adaptor can comprise an engaging portion, andthe output member can comprise a holding portion. The engaging portioncan abut against the holding portion or release from the holding portionto bring the transmission mechanism into an assembled state or adisassembled state.

In some embodiments, the output member can comprise a holding member andan output gear connected to the holding member. The holding member canabut against the adaptor or release from the adaptor to bring thetransmission mechanism into the assembled state or the disassembledstate. The output member can output the power to the imaging elementthrough the output gear.

In some embodiments, the holding portion can be formed on the holdingmember.

In some embodiments, the engaging portion can comprise a plurality ofprotruding blocks, a slot being formed between two adjacent protrudingblocks. The holding portion can comprise a plurality of protrusionscorresponding to the slots. The protrusions can engage into or disengagefrom the corresponding slots to cause the engaging portion abut againstthe holding portion or release from the holding portion.

In some embodiments, the adaptor can comprise a transmission shaft. Theengaging portion can be provided at an end portion of the transmissionshaft. The plurality of protruding blocks can be arranged along acircumference of an end face of the transmission shaft with an intervaltherebetween.

In some embodiments, two engaging portions can be respectively providedat two ends of the transmission shaft.

In some embodiments, the adaptor can further comprise a transmissionwheel for connecting the power device. A mounting portion can be formedon the transmission shaft at which the transmission wheel can beprovided. The mounting portion can prevent a movement of thetransmission wheel relative to the transmission shaft along acircumferential direction and an axial direction of the transmissionshaft.

In some embodiments, four mounting portions can be evenly arranged alongthe circumferential direction of the transmission shaft.

In some embodiments, the transmission wheel can comprise a plurality ofgear teeth through which the transmission wheel can be meshed with thepower device.

In some embodiments, an angle between a lengthwise direction of the gearteeth and an axial direction of a central axis of the transmission wheelcan be an acute angle.

In some embodiments, the locking member can pass through the output gearand the holding member and be threadedly connected to or disconnectedfrom the adaptor to cause the holding member abut against the adaptor orrelease from the adaptor.

In some embodiments, the locking member can comprise a connecting rod,the connecting rod being threadedly connected to or disconnected fromthe transmission shaft to cause the holding member abut against theadaptor or release from the adaptor.

In some embodiments, the transmission shaft can be provided with anaccommodating hole. A collar can extend from a position at a middle ofan inner wall of the accommodating hole. The adaptor can be threadedlyconnected to or disconnected from the connecting rod through the collar.

In some embodiments, a thread can be formed on a surface of the collarfacing a central axis of the transmission shaft.

In some embodiments, the holding member can be provided with a via hole,and the output gear can be provided with a through hole and a groove incommunication with the through hole. The holding member can be mountedwithin the groove. The locking member can protrude from the holdingmember upon passing through the through hole and the via hole.

In some embodiments, the plurality of protrusions can be arranged alonga circumference of the via hole.

In some embodiments, the holding member can be provided with a guidehole. A rib can be fixed on a bottom surface of the groove facing theholding member. The rib can be inserted into the guide hole to guide aconnection between the output gear and the holding member.

In some embodiments, the output gear can comprise a meshing portionthrough which the output gear can drive a rotation of the imagingelement.

In some embodiments, two output members can be provided each of whichbeing detachably connected to the adaptor through the locking member.The adaptor can drive a coaxial rotation of the two output members.

Another aspect of the present disclosure provides a transmissionmechanism for transmitting a power of a power device, the transmissionmechanism comprising an output member and a worm wheel shaft connectedto the power device to transmit the power of the power device to theoutput member. The output member can output the power. The worm wheelshaft can drive a coaxial rotation of the output member by a rotation ofthe worm wheel shaft to output the power. The worm wheel shaft and theoutput member can be engaged with each other through a relative movementalong an axial direction. The engagement can limit a relative rotationbetween the worm wheel shaft and the output member.

In some embodiments, the transmission mechanism can further comprise alocking member rotatably provided on the output member. The lockingmember can pass through the output member along an axial direction ofthe output member. An operating portion provided on the locking membercan be operated to connect the locking member with the worm wheel shaftor disconnect locking member from the worm wheel shaft. The relativemovement between the worm wheel shaft and the output member can belimited when the locking member is connected with the worm wheel shaft.

In some embodiments, the worm wheel shaft can comprise an engagingportion, the output member can comprise a holding portion, and theengaging portion and the holding portion can abut against or releasefrom each other to bring the transmission mechanism into an assembledstate or a disassembled state.

In some embodiments, the output member can comprise a holding member andan output gear connected to the holding member. The holding member canabut against the worm wheel shaft or release from the worm wheel shaftto bring the transmission mechanism into the assembled state or thedisassembled state. The output member can output the power to a loadthrough the output gear.

In some embodiments, the holding portion can be formed on the holdingmember.

In some embodiments, the engaging portion can comprise a plurality ofprotruding blocks, a slot being formed between two adjacent protrudingblocks. The holding portion can comprise a plurality of protrusionscorresponding to the slots. The protrusions can engage into or disengagefrom the corresponding slots to cause the engaging portion abut againstthe holding portion or release from the holding portion.

In some embodiments, the worm wheel shaft can comprise a transmissionshaft. The engaging portion can be provided at an end portion of thetransmission shaft. The plurality of protruding blocks can be arrangedalong a circumference of an end face of the transmission shaft with aninterval therebetween.

In some embodiments, two engaging portions can be respectively providedat two ends of the transmission shaft.

In some embodiments, the locking member can pass through the output gearand the holding member and be threadedly connected to or disconnectedfrom the worm wheel shaft to abut the holding member against the wormwheel shaft to or release the holding member from the worm wheel.

In some embodiments, the locking member can comprise a connecting rod,the connecting rod being threadedly connected to or disconnected fromthe transmission shaft to cause the holding member abut against the wormwheel shaft or release from the worm wheel shaft.

In some embodiments, the transmission shaft can be provided with anaccommodating hole. A collar can extend from a position at a middle ofan inner wall of the accommodating hole, and the worm wheel shaft can bethreadedly connected to or disconnected from the connecting rod throughthe collar.

In some embodiments, a thread can be formed on a surface of the collarfacing a central axis of the transmission shaft.

In some embodiments, the holding member can be provided with a via hole,and the output gear can be provided with a through hole and a groove incommunication with the through hole. The holding member can be mountedwithin the groove. The locking member can protrude from the holdingmember upon passing through the through hole and the via hole.

In some embodiments, the plurality of protrusions can be arranged alonga circumference of the via hole with an interval therebetween.

In some embodiments, the holding member can be provided with a guidehole. A rib can be fixed on a bottom surface of the groove facing theholding member. The rib can be inserted into the guide hole to guide aconnection between the output gear and the holding member.

In some embodiments, the output gear can comprise a meshing portionthrough which the output gear can drive a rotation of the load.

Another aspect of the present disclosure provides a follow focusactuator, the follow focus actuator comprising a casing, a power deviceand a transmission mechanism connected to the casing for transmitting apower of the power device, the transmission mechanism comprising anoutput member and a worm wheel shaft connected to the power device totransmit the power of the power device to the output member. The outputmember can output the power. The worm wheel shaft can drive a coaxialrotation of the output member by a rotation of the worm wheel shaft tooutput the power. The worm wheel shaft and the output member can beengaged with each other through a relative movement along an axialdirection. The engagement can limit a relative rotation between the wormwheel shaft and the output member.

In some embodiments, the transmission mechanism can further comprise alocking member rotatably provided on the output member. The lockingmember can pass through the output member along an axial direction ofthe output member. An operating portion provided on the locking membercan be operated to connect the locking member with the worm wheel shaftor disconnect locking member from the worm wheel shaft. The relativemovement between the worm wheel shaft and the output member can belimited when the locking member is connected with the worm wheel shaft.

In some embodiments, the power device can be provided within the casing.The transmission mechanism can be provided on the casing through theworm wheel shaft. The transmission mechanism can be connected to thepower device through the worm wheel shaft. The power device can drive arotation of the output member through the worm wheel shaft.

In some embodiments, a clearing slot can be provided on the casing foraccommodating the output member upon assembling the follow focusactuator.

In some embodiments, two clearing slots can be provided facing away fromeach other.

In some embodiments, the casing can be provided with a housing hole incommunication with the clearing slot. The worm wheel shaft can bemounted within the housing hole.

In some embodiments, a receiving cavity in communication with thehousing hole can be formed in the casing. The power device can bereceived in the receiving cavity.

In some embodiments, the power device can comprise an output shaftmeshed with the worm wheel shaft to drive the rotation of the worm wheelshaft.

In some embodiments, the follow focus actuator can further comprise alatching member connected to the casing. The follow focus actuator canbe detachably connected to a carrier through the latching member.

In some embodiments, the latching member can comprise a knob movablyconnected to the casing, a stationary portion connected to the casingand a movable portion rotatably connected to the stationary portion. Theknob can be rotatable relative to the casing to bring the latchingmember into a locked state or a disassembled state.

In some embodiments, the movable portion can be connected to the knob.The knob can drive a rotation of the movable portion relative to thestationary portion.

In some embodiments, a receiving hole for receiving the carrier can beformed by the movable portion and the stationary portion when thelatching member is in the locked state.

In some embodiments, the worm wheel shaft can comprise an engagingportion, and the output member can comprise a holding portion. Theengaging portion can abut against the holding portion or release fromclearing slot to bring the transmission mechanism into an assembledstate or a disassembled state.

In some embodiments, the output member can comprise a holding member andan output gear connected to the holding member. The holding member canabut against the worm wheel shaft or release from the worm wheel shaftto bring the transmission mechanism into the assembled state or thedisassembled state. The output member can output the power to a loadthrough the output gear.

In some embodiments, the holding portion can be formed on the holdingmember.

In some embodiments, the engaging portion can comprise a plurality ofprotruding blocks, a slot being formed between two adjacent protrudingblocks. The holding portion can comprise a plurality of protrusionscorresponding to the slots. The protrusions can engage into or disengagefrom the corresponding slots to cause the engaging portion abut againstthe holding portion or release from the holding portion.

In some embodiments, the worm wheel shaft can comprise a transmissionshaft. The engaging portion can be provided at an end portion of thetransmission shaft. The plurality of protruding blocks cam be arrangedalong a circumference of an end face of the transmission shaft with aninterval therebetween.

In some embodiments, two engaging portions can be respectively providedat two ends of the transmission shaft.

In some embodiments, the locking member can pass through the output gearand the holding member and be threadedly connected to or disconnectedfrom the worm wheel shaft to abut the holding member against the wormwheel shaft to or release the holding member from the worm wheel.

In some embodiments, the locking member can comprise a connecting rod,the connecting rod being threadedly connected to or disconnected fromthe transmission shaft to cause the holding member abut against the wormwheel shaft or release from the worm wheel shaft.

In some embodiments, the transmission shaft can be provided with anaccommodating hole. A collar can extend from a position at a middle ofan inner wall of the accommodating hole, and the worm wheel shaft can bethreadedly connected to or disconnected from the connecting rod throughthe collar.

In some embodiments, a thread can be formed on a surface of the collarfacing a central axis of the transmission shaft.

In some embodiments, the holding member can be provided with a via hole,and the output gear can be provided with a through hole and a groove incommunication with the through hole. The holding member can be mountedwithin the groove. The locking member can protrude from the holdingmember upon passing through the through hole and the via hole.

In some embodiments, the plurality of protrusions can be arranged alonga circumference of the via hole with an interval therebetween.

In some embodiments, the holding member can be provided with a guidehole. A rib can be fixed on a bottom surface of the groove facing theholding member. The rib can be inserted into the guide hole to guide aconnection between the output gear and the holding member.

In some embodiments, the output gear can comprise a meshing portionthrough which the output gear can drive a rotation of the load.

In some embodiments, two output members can be provided each of whichbeing detachably connected to the worm wheel shaft through the lockingmember. The worm wheel shaft can drive a coaxial rotation of the twooutput members.

Another aspect of the present disclosure provides an imaging device, theimaging device comprising a gimbal, an imaging element provided on thegimbal and a follow focus actuator provided on the gimbal, the followfocus actuator comprising a casing and a power device, and furthercomprising a transmission mechanism connected to the casing fortransmitting a power of the power device, the transmission mechanismcomprising an output member and a worm wheel shaft connected to thepower device to transmit the power of the power device to the outputmember. The output member can output the power to the imaging element.The worm wheel shaft can drive a coaxial rotation of the output memberby a rotation of the worm wheel shaft to output the power. The wormwheel shaft and the output member can be engaged with each other througha relative movement along an axial direction. The engagement can limit arelative rotation between the worm wheel shaft and the output member.

In some embodiments, the transmission mechanism can further comprise alocking member rotatably provided on the output member. The lockingmember can pass through the output member along an axial direction ofthe output member. An operating portion provided on the locking membercan be operated to connect the locking member with the worm wheel shaftor disconnect locking member from the worm wheel shaft. The relativemovement between the worm wheel shaft and the output member can belimited when the locking member is connected with the worm wheel shaft.

In some embodiments, the gimbal can comprise a carrier, a carryingplatform and a mounting rod provided on the carrier, a first operatinghandle and a second operating handle connected to the mounting rod, anda carrying rod connected to the carrying platform. The imaging elementcan be provided on the carrying platform. The follow focus actuator canbe connected to the carrying rod.

In some embodiments, the follow focus actuator can comprise a gear ring.The gear ring can be sleeved on a lens ring of the imaging element. Thegear ring can be meshed with the output member. The power device candrive a rotation of the gear ring through the adaptor to effect afocusing of the imaging element. Or, the gear ring can be sleeved on anaperture ring of the imaging element and meshed with the output member,and the power device can drive a rotation of the gear ring through theadaptor to effect an aperture adjustment of the imaging element.

In some embodiments, the power device can be provided within the casing.The transmission mechanism can be provided on the casing through theworm wheel shaft. The transmission mechanism can be connected to thepower device through the worm wheel shaft. The power device can drive arotation of the output member through the worm wheel shaft.

In some embodiments, a clearing slot can be provided on the casing foraccommodating the output member upon assembling the follow focusactuator.

In some embodiments, two clearing slots can be provided facing away fromeach other.

In some embodiments, the casing can be provided with a housing hole incommunication with the clearing slot. The worm wheel shaft can bemounted within the housing hole.

In some embodiments, a receiving cavity in communication with thehousing hole can be formed in the casing. The power device can bereceived in the receiving cavity.

In some embodiments, the power device can comprise an output shaftmeshed with the worm wheel shaft to drive the rotation of the worm wheelshaft.

In some embodiments, the follow focus actuator can further comprise alatching member connected to the casing. The follow focus actuator canbe detachably connected to the gimbal through the latching member.

In some embodiments, the latching member can comprise a knob movablyconnected to the casing, a stationary portion connected to the casingand a movable portion rotatably connected to the stationary portion. Theknob can be rotatable relative to the casing to bring the latchingmember into a locked state or a disassembled state.

In some embodiments, the movable portion can be connected to the knob,and the knob can drive a rotation of the movable portion relative to thestationary portion.

In some embodiments, a receiving hole for receiving the carrier can beformed by the movable portion and the stationary portion when thelatching member is in the locked state.

In some embodiments, the worm wheel shaft can comprise an engagingportion, and the output member can comprise a holding portion. Theengaging portion can abut against the holding portion or release fromthe holding portion to bring the transmission mechanism into anassembled state or a disassembled state.

In some embodiments, the output member can comprise a holding member andan output gear connected to the holding member. The holding member canabut against the worm wheel shaft or release from the worm wheel shaftto bring the transmission mechanism into the assembled state or thedisassembled state. The output member can output the power to theimaging element through the output gear.

In some embodiments, the holding portion can be formed on the holdingmember.

In some embodiments, the engaging portion can comprise a plurality ofprotruding blocks, a slot being formed between two adjacent protrudingblocks. The holding portion can comprise a plurality of protrusionscorresponding to the slots. The protrusions can engage into or disengagefrom the corresponding slots to cause the engaging portion abut againstthe holding portion or release from the holding portion.

In some embodiments, the worm wheel shaft can comprise a transmissionshaft. The engaging portion can be provided at an end portion of thetransmission shaft, The plurality of protruding blocks can be arrangedalong a circumference of an end face of the transmission shaft with aninterval therebetween.

In some embodiments, two engaging portions can be respectively providedat two ends of the transmission shaft.

In some embodiments, the locking member can pass through the output gearand the holding member and be threadedly connected to or disconnectedfrom the worm wheel shaft to abut the holding member against the wormwheel shaft to or release the holding member from the worm wheel.

In some embodiments, the locking member can comprise a connecting rod,the connecting rod being threadedly connected to or disconnected fromthe transmission shaft to cause the holding member abut against the wormwheel shaft or release from the worm wheel shaft.

In some embodiments, the transmission shaft can be provided with anaccommodating hole. A collar can extend from a position at a middle ofan inner wall of the accommodating hole, and the worm wheel shaft can bethreadedly connected to or disconnected from the connecting rod throughthe collar.

In some embodiments, a thread can be formed on a surface of the collarfacing a central axis of the transmission shaft.

In some embodiments, the holding member can be provided with a via hole,and the output gear can be provided with a through hole and a groove incommunication with the through hole. The holding member can be mountedwithin the groove. The locking member can protrude from the holdingmember upon passing through the through hole and the via hole.

In some embodiments, the plurality of protrusions can be arranged alonga circumference of the via hole with an interval therebetween.

In some embodiments, the holding member can be provided with a guidehole. A rib can be fixed on a bottom surface of the groove facing theholding member. The rib can be inserted into the guide hole to guide aconnection between the output gear and the holding member.

In some embodiments, the output gear can comprise a meshing portionthrough which the output gear can drive a rotation of the imagingelement.

In some embodiments, two output members can be provided each of whichbeing detachably connected to the worm wheel shaft through the lockingmember. The worm wheel shaft can drive a coaxial rotation of the twooutput members.

In some embodiments, the gimbal can further comprise a control assemblythrough which the imaging element can be provided on the gimbal.

In some embodiments, the control assembly can comprise a measuring partand a controller, the measuring part being configured to obtain a statusinformation of the imaging element, the controller being configured tocalculate an attitude information of the imaging element based upon thestatus information and output one or more motor signals based upon theattitude information. The gimbal can further comprise a motor assemblyconfigured to directly drive the gimbal based upon the one or more motorsignals to effect a rotation of the imaging element about at least oneof a pitch axis, a roll axis or a yaw axis of the gimbal.

In some embodiments, the measuring part can comprise an inertialmeasurement unit (IMU).

With the transmission mechanism, the follow focus, the follow focusactuator and the imaging device of the disclosure, the adaptor and theoutput member can be engaged with each other through a relative movementin an axial direction. The engagement can limit a relative rotationbetween the adaptor and the output member. The transmission mechanismcan comprise a locking member rotatably provided on the output member.The locking member can pass through the output member along an axialdirection of the output member. An operating portion provided on thelocking member can be operated to connect the locking member to ordisconnect the locking member from the adaptor, thereby a convenientattachment and/or detachment of the transmission mechanism is effected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded view of a transmission mechanism in accordancewith embodiments of the disclosure.

FIG. 2 shows an exploded view of the transmission mechanism of FIG. 1from another point of view.

FIG. 3 shows a holding member and a transmission shaft of thetransmission mechanism of FIG. 1.

FIG. 4 shows an exploded view of the holding member and the transmissionshaft of the transmission mechanism of FIG. 3.

FIG. 5 shows a follow focus having the transmission mechanism of FIG. 1in accordance with a first embodiment of the disclosure.

FIG. 6 shows an exploded view of the follow focus of FIG. 5.

FIG. 7 shows an exploded view of the follow focus of FIG. 5 from anotherpoint of view.

FIG. 8 shows the transmission mechanism and a power device of the followfocus of FIG. 5.

FIG. 9 shows an exploded view of the transmission mechanism and thepower device of FIG. 8.

FIG. 10 shows an exploded view of the transmission mechanism and thepower device of FIG. 8 from another point of view.

FIG. 11 shows a cross-sectional view of the transmission mechanism andthe power device of FIG. 8 along an XI-XI line.

FIG. 12 shows a cross-sectional view of the follow focus of FIG. 5 alongan XII-XII line.

FIG. 13 shows a follow focus having the transmission mechanism of FIG. 1in accordance with a second embodiment of the disclosure.

FIG. 14 shows an imaging device having the follow focus of FIG. 5 inaccordance with embodiments of the disclosure.

LIST OF REFERENCE NUMERALS

TABLE 1 Transmission mechanism 100 Adaptor  10 Transmission shaft  11Mounting portion 111 Engaging portion 112 Protruding block 113 Slot 114Accommodating hole 115 Collar 116 Transmission wheel  12 Shaft hole 121Gear tooth 122 Holding member  20 Body  21 First surface 211 Secondsurface 212 Via hole 213 Guide hole 214 Screw hole 215 Holding portion 22 Protrusion 221 Output gear  30 First end face  31 Second end face 32 Through hole  33 Stepped hole  34 Groove  35 Receiving slot 351Guide strip  36 Connector  37 Meshing portion  38 Rib 381 Locking member 40 Operating portion  41 Step portion 411 Fixing surface 412 Connectingrod  42 External thread 421 Follow focus 200, 300 Casing  50 Latchingmember  51 Knob 511 Stationary portion 512 Movable portion 513 Receivinghole 514 Clearing slot  52 Housing hole 521 Receiving cavity  53 Powerdevice  60 Output shaft  61 Screw tooth 611 Imaging device 400 Gimbal 70 Carrier  71 Carrying platform  72 Mounting rod  73 First operatinghandle  74 Second operating handle  75 Carrying rod  76 Imaging element 80 Gear ring  81 Output member  90

Illustrative embodiments of the disclosure will be described withreference to the drawings.

DETAILED DESCRIPTION OF THE DISCLOSURE

Illustrative embodiments of the disclosure are described with referenceto the drawings. The embodiments and features can be combined with oneanother provided that they are technically compatible.

Referring to FIGS. 1-4, a transmission mechanism 100 in accordance withembodiments of the disclosure can comprise an adaptor 10, an outputmember 90 and a locking member 40. The adaptor 10 can be detachablyconnected to the output member 90.

The adaptor 10 can be connected to a power device and transmit a powerfrom the power device to the output member, such that the output member90 can output the power. The adaptor 10 can drive a coaxial rotation ofthe output member 90 to allow the output member 90 to output the power.The adaptor 10 and the output member 90 can be engaged to or disengagedfrom each other by a relative movement along an axial direction, suchthat the transmission mechanism 100 can be brought into an assembledstate or a disassembled state. The engagement can limit a relativerotation between the adaptor 10 and the output member 90. The lockingmember 40 can be rotatably provided on the output member 90. The lockingmember 40 can pass through the output member 90 along an axial directionof the output member 90, and be detachably connected to the adaptor 10.A relative movement between the adaptor 10 and the output member 90along an axial direction can be limited once the locking member 40 isconnected with the adaptor 10.

The output member 90 can comprise a holding member 20 and an output gear30. The locking member 40 can be movably connected to the output gear 30and the holding member 20. The locking member 40 can be rotated relativeto the output member 90 and be connected to or disconnected from theadaptor 10 during the rotation, such that the holding member 20 and theadaptor 10 can be engaged or disengaged, thereby the transmissionmechanism 100 is attached or detached.

The adaptor 10 can be connected to the power device. The adaptor 10 canbe engaged to or disengaged from the output member 90 by connecting toor disconnecting from the locking member 40 thereby bringing thetransmission mechanism 100 into the assembled state or the disassembledstate. The adaptor 10 can comprise a transmission shaft 11 and atransmission wheel 12. The transmission shaft 11 can be coupled to thetransmission wheel 12 and rotate coaxially with the transmission wheel12. The power device can drive a rotation of the transmission shaft 11by the transmission wheel 12.

A mounting portion 111 can be formed on the transmission shaft 11. Themounting portion 111 can prevent a movement of the transmission wheel 12relative to the transmission shaft 11 along a circumferential directionand an axial direction of the transmission shaft 11. In someembodiments, the mounting portion 111 can be a plane. In someembodiments, the mounting portion 111 can comprise four mountingportions 111 which are equally arranged along the circumferentialdirection of the transmission shaft 111. It will be appreciated that,the number of the mounting portions 111 is not limited to that describedin the illustrative embodiments. For instance, the number of themounting portions can be more than four or less than four. An engagingportion 112 can be formed at each end of the transmission shaft 11. Theengaging portion 112 can abut against or release from the holding member20 to bring the transmission mechanism 100 into the assembled state orthe disassembled state. In some embodiments, the engaging portion 112can comprise a plurality of protruding blocks 113 provided on an endface of the transmission shaft 11. In some embodiments, the plurality ofprotruding blocks 113 can be arranged along a circumference of the endface of the transmission shaft 11 with an interval therebetween. A slot114 can be formed between two adjacent protruding blocks 113. The slot114 can be meshed with the holding member 20 to engage the adaptor 10with the holding member 20.

The transmission shaft 11 can be provided with an accommodating hole115. A central axis of the accommodating hole 115 can substantiallycoincide with a central axis of the transmission shaft 11. A collar 116can extend from a position at a middle of an inner wall of theaccommodating hole 115 (refer to FIG. 11). The collar 116 can extendalong a circumferential direction of the accommodating hole 115. Thetransmission shaft 11 can be connected to the locking member 40 throughthe collar 116. A thread can be formed on a surface of the collar 116facing a central axis thereof. The thread can be meshed with the lockingmember 40 to connect or disconnect the transmission shaft 11 with thelocking member 40. It will be appreciated that, the collar 116 can beomitted in alternative embodiments. For instance, a thread can be formedon the inner wall of the accommodating hole 115, and the thread on theinner wall of the accommodating hole 115 can be meshed with the lockingmember 40, such that the transmission shaft 11 and the locking member 40can be connected to or disconnected from each other.

The transmission wheel 12 can be sleeved on the transmission shaft 11.The transmission wheel 12 can be meshed with the power device to drive arotation of the transmission shaft 11. In some instances, thetransmission wheel 12 can be meshed with the mounting portion 111 of thetransmission shaft 11, such that a movement of the transmission wheel 12relative to the transmission shaft 11 along the circumferentialdirection and the axial direction of the transmission shaft 11 can belimited by the mounting portion 111. The transmission wheel 12 can beprovided with a shaft hole 121, within which the transmission shaft 11can be partially received. The mounting portion 111 and the shaft hole121 can be meshed with each other, and the transmission wheel 12 can beprovided on the mounting portion 111 through the shaft hole 121. Thetransmission wheel 12 can comprise a plurality of gear teeth 122,through which the transmission wheel 12 can be meshed with the powerdevice. The transmission wheel 12 can be provided in a substantiallydisk-like shape. The plurality of gear teeth 122 can be arranged on acircumference of the transmission wheel 12 with an intervaltherebetween. An angle between a lengthwise direction of each one of thegear teeth 122 and an axial direction of a central axis of thetransmission wheel 12 can be an acute angle. In some embodiments, theadaptor 10 can be a worm wheel shaft, and the transmission wheel 12 canbe a worm wheel.

The holding member 20 can be detachably connected to the adaptor 10. Theholding member 20 can comprise a body 21 and a holding portion 22provided on the body 21. The holding portion 22 can abut against orrelease from the engaging portion 112 to cause the holding member 20 andthe adaptor 10 to abut against or release from each other. The body 21can comprise a first surface 211 and a second surface 212 facing awayfrom each other. The holding portion 22 can be provided on the firstsurface 211. The body 21 can be provided with a via hole 213 throughwhich the locking member 40 passes. The via hole 213 can penetratethrough the first surface 211 and the second surface 212.

The body 21 can be provided with a guide hole 214 and a screw hole 215.The guide hole 214 can be an arc-shaped hole for guiding a connectionbetween the holding member 20 and the output gear 30. The holding member20 can be connected to the output gear 30 through the screw hole 215. Insome embodiments, three guide holes 214 and three screw holes 215 can beprovided. The three guide holes 214 and the three screw holes 215 can bespaced apart from each other and equally arranged along a circle havinga center coinciding on a central axis of the via hole 213. It will beappreciated that, in other embodiments, the number of the guide holes214 or the screw holes 215 can vary according to actual requirements.

The holding portion 22 can comprise a plurality of protrusions 221meshed with the slots 114. The protrusions 221 can be engaged into ordisengaged from the slots 114 to cause the holding member 20 and theadaptor 10 to abut against or release from each other. A shape and aposition of the plurality of protrusions 221 can correspond to a shapeand a position of the plurality of slots 114. In some embodiments, theplurality of protrusions 221 can be arranged along a circumference ofthe via hole 213 with an interval therebetween.

The output gear 30 can be connected to the holding member 20 and thelocking member 40 to drive a rotation of a load, such as a lens ring ofan imaging device. The output gear 30 can comprise a first end face 31and a second end face 32 facing away from each other. The first end face31 can be proximal to the locking member 40 while the second end face 32can be distal to the locking member 40. The output gear 30 can beprovided with a through hole 33, within which the locking member 40 canbe partially received. The output gear 30 can be provided with a steppedhole 34, through which the output gear 30 can be connected to theholding member 20.

In some embodiments, three stepped hole 34 can be provided. Positions ofthe three stepped holes 34 can correspond to positions of the threescrew holes 215. Three connectors 37 can be respectively received withinthe three stepped holes 34 and the three screw holes 215, such that theoutput gear 30 is connected with the holding member 20. In someembodiments, the connectors 37 can be screws. It will be appreciatedthat, in other embodiments, the connectors 37 can be provided as otherparts such as bolts or pins. The output gear 30 and the holding member20 can be connected to each other by other means.

The output gear 30 can be provided with a groove 35. The groove 35 canpenetrate through the second end face 32 and be in communication withthe stepped holes 34 and the through hole 33 to receive the holdingmember 20. A bottom surface of the groove 35 facing the holding member20 can be provided with a receiving slot 351 which is in communicationwith the through hole 33. A size of the receiving slot 351 in adirection perpendicular to an axial direction of the output gear 30 canbe greater than a size of the through hole 33 in a directionperpendicular to the axial direction of the output gear 30. A guidestrip 36 can be fixed on the bottom surface of the groove 35 facing theholding member 20. The guide strip 36 can be inserted into the guidehole 214 to provide a guidance in connecting the output gear 30 with theholding member 20. A shape of the guide strip 36 can correspond to ashape of the guide hole 214. In some embodiments, three guide strips 36can be provided. Positions of the three guide strips 36 can correspondto positions of the three guide holes 214. The three guide strips 36 canbe equally arranged along a circumference of the receiving slot 351. Itwill be appreciated that, in other embodiments, the number of the guidestrips 36 can vary according to actual requirements.

The output gear 30 can comprise a meshing portion 38 through which theload can be driven by the output gear 30. In some embodiments, themeshing portion 38 can comprise a plurality of ribs 381. The output gear30 can be provided in a substantially disk-like shape. The plurality ofribs 381 can be equally arranged along a circumference of the outputgear 30. The meshing portion 38 can be meshed with the load to drive theload. In some embodiments, the rib 381 can be a gear teeth.

It will be appreciated that, the holding member 20 can be integrallyformed with the output gear 30. Optionally, the holding portion 22 canbe directly formed on the output gear 30 without providing a separateholding member 20.

The locking member 40 can be movably connected to the output gear 30 andthe holding member 20. The locking member 40 can be connected to ordisconnected from the adaptor 10 by a rotation relative to the outputgear 30 and the holding member 20. The locking member 40 can comprise anoperating portion 41 and a connecting rod 42 fixedly connected to theoperating portion 41. The connecting rod 42 can be meshed with thecollar 116 to connect the locking member 40 to or disconnect the lockingmember 40 from the adaptor 10. The operating portion 41 can be operatedto engage the locking member 40 to the adaptor 10 or disengage thelocking member 40 from the adaptor 10.

The operating portion 41 can be provided in a substantially steppedshape. The operating portion 41 can comprise a step portion 411 to bereceived within the receiving slot 351. The step portion 411 cancomprise a fixing surface 412 facing the holding portion 20. Theconnecting rod 42 can be fixed on the fixing surface 412. In someembodiments, a size of the step portion 411 in a direction perpendicularto the axial direction of the output gear 30 can be greater than thesize of the through hole 33 in a direction perpendicular to the axialdirection of the output gear 30. An external thread 421 can be providedon the connecting rod 42. The external thread 421 can be threadedlymeshed with the thread of the collar 116. The locking member 40 can beconnected with the adaptor 10 by a threaded connection between theexternal thread 421 and the thread of the collar 116.

In assembling the transmission mechanism, the operating portion 41 ofthe locking member 40 can be inserted into the through hole 33, and thestep portion 411 of the operating portion 41 can be received within thereceiving slot 351. The three connectors 37 can be respectively receivedwithin the three stepped holes 34 and the three screw holes 215, and thethree guide strips 36 can be respectively inserted into the three guideholes 214, such that the output gear 30 can be fixedly connected to theholding member 20. The holding member 20 can be received within thegroove 35. The connecting rod 42 of the locking member 40 can passthrough the via hole 213 and protrude from the holding member 20. Theoperating portion 41 can be partially received within the through hole33, with the fixing surface 412 and the holding member 20 facing eachother. It will be appreciated that, in other embodiments, the guidestrips 36 and the guide holes 214 can be omitted.

The step portion 411 of the operating portion 41 can be received withinthe receiving slot 351. The step portion 411 can be positioned betweenthe holding member 20 and a bottom surface of the receiving slot 351.The size of the step portion 411 in a direction perpendicular to theaxial direction of the output gear 30 can be greater than the size ofthe through hole 33 in a direction perpendicular to the axial directionof the output gear 30, such that the locking member 40 can be preventedfrom releasing from the output gear 30. The holding member 20 can befixedly connected to the output gear 30 and cover the receiving slot351, such that a release of the locking member 40 from the receivingslot 351 and the groove 35 of the output gear 30 can be prevented by theholding member 20.

The external thread of the connecting rob 42 can be threadedly connectedto the thread of the collar 116 by rotating the operating portion 41along a predetermined direction by a predetermined angle, such that theconnecting rod 42 can be partially received in the collar 116. Theprotrusions 221 of the holding member 20 can be engaged into the slots114 of the adaptor 10, such that the holding member 20 and the adaptor10 can abut against each other through the engaging portion 112 and theholding portion 22 to bring the transmission mechanism 100 into theassembled state. The connecting rod 42 can be gradually disengaged fromthe collar 116 by rotating the operating portion 41 along a directionopposite to the predetermined direction by the predetermined angle, suchthat the locking member 40 can be disengaged from the adaptor 10. Theholding member 20 can be detached from the adaptor 10, and theprotrusions 211 can be detached from the slots 114 to bring thetransmission mechanism 100 into the disassembled state.

Referring to FIGS. 5-12, a follow focus 200 in accordance with a firstembodiment of the disclosure can comprise the transmission mechanism100, a casing 50 and a power device 60. The transmission mechanism 100can be connected to the casing 50. The power device 60 can provide powerto the transmission mechanism 100, and the transmission mechanism 100can drive a load. In some embodiments, the power device 60 can beprovided within the casing 50, the transmission mechanism 100 can beprovided on the casing 50 through the adaptor 10, and the adaptor 10 canbe connected to the power device 60. The power device 60 can drive arotation of the output gear 30 through the adaptor 10.

The casing 50 can be connected to a latching member 51 through which thecasing 50 can be detachably connected to a carrier. The latching member51 can comprise a knob 511, a stationary portion 512 and a movableportion 513. The knob 511 can be movably connected to the casing 50, andcan be capable of rotating relative to the casing 50 to bring thelatching member 51 into a locked state or a rotatable state. Thestationary portion 512 can be rotatably connected to one end of themovable portion 513, and the other end of the movable portion 513 can beconnected to the knob 51. The knob 511 can drive a movement of themovable portion 513, such that the movable portion 513 can be rotatedrelative to the stationary portion 512 to bring the latching member 51into the locked state or the rotatable state. When the latching member51 is in the locked state, a receiving hole 514 for partially receivingthe carrier can be formed by the movable portion 513 and the stationaryportion 512.

A clearing slot 52 can be formed on the casing 50 to accommodate theoutput member 90 upon assembling the follow focus 200. In someembodiments, two clearing slot 52 can be provided facing away from eachother. The casing 50 can be provided with a housing hole 521 incommunication with the clearing slots 52. The adaptor 10 can be mountedwithin the housing hole 521, and the engaging portion 112 can protrudefrom the housing hole 521. The casing 50 can be provided with areceiving cavity 53 in communication with the housing hole 521. Thepower device 60 can be received in the receiving cavity 53. The powerdevice 60 can comprise an output shaft 61 which is meshed withtransmission wheel 12 of the adaptor 10. The power device 60 can drivethe adaptor 10 through the output shaft 61 and the transmission wheel12. A lengthwise direction of the output shaft 61 can be substantiallyperpendicular to an axial direction of a central axis of the adaptor 10.Screw teeth 611 can be provided on a circumference of the output shaft61. The screw teeth 611 can be meshed with the gear teeth 122 of thetransmission wheel 12 to drive a rotation of the adaptor 10.

Referring to FIG. 13, a follow focus 300 in accordance with a secondembodiment of the disclosure is shown. The follow focus 300 can besubstantially similar to the follow focus 200, except that the followfocus 300 can comprise two output members 90. The two output members 90can be detachably connected to the engaging portions 112 at two ends ofthe transmission shaft 11 of the adaptor 10 respectively through alocking member 40. The adaptor 10 can drive a synchronous rotation ofthe two holding members 20. The two clearing slots 52 can respectivelyaccommodate the two holding members 20, the two output gears 30 and thetwo locking members 40.

Referring to FIG. 14, an imaging device 400 in accordance withembodiments of the disclosure can comprise a follow focus 200, a gimbal70 and an imaging element 80. The imaging element 80 and the followfocus 200 can be provided on the gimbal 70. The follow focus 200 candrive a focusing of the imaging element 80. In some embodiments, theimaging element 80 can be a camera. It will be appreciated that, inother embodiments, the imaging element 80 can be other image capturingelement such as a video camera. The gimbal 70 can be a carrier, and theimaging element 80 can be a load. The gimbal 70 can comprise a carrier71, a carrying platform 72, a mounting rod 73, a first operating handle74, a second operating handle 75 and a carrying rod 76. The carryingplatform 72 and the mounting rod 73 can be provided on the carrier 71,and the imaging element 80 can be installed on the carrying platform 72.The first operating handle 74 and the second operating handle 75 can beconnected to the mounting rod 73 and can facilitate a photographer togrip or a mounting to other parts. The carrying rod 76 can be connectedto the carrying platform 72 and can be mounted in the receiving hole 514of the latching member 51. The follow focus 200 can be detachablyconnected at an arbitrary position on the carrying rod 76 of the gimbal70 through the latching member 51.

The follow focus 200 can comprise a gear ring 81 sleeved on a lens ringof the imaging element 80. A central axis of the gear ring 81 can besubstantially perpendicular to a central axis of the output gear 30. Thepower device 60 can drive the transmission mechanism 100. Thetransmission mechanism 100 can drive a rotation of the gear ring 81through the output gear 30 to rotate the lens ring of the imagingelement 80, thereby a focusing is effected. It will be appreciated that,in other embodiments, the imaging device 400 can employ another type offollow focus such as the follow focus 300 in place of the follow focus200. The follow focus 300 can drive the rotation of the lens ring of theimaging element 80 through the gear ring 81 to effect a focusing.

It will be appreciated that, the gear ring 81 can be sleeved directly onan aperture ring of the imaging element 80. The power device 60 candrive the transmission mechanism 100, and the transmission mechanism 100can drive the rotation of the gear ring 81 through the output gear 30 torotate the aperture ring of the imaging element 80, thereby an apertureadjustment is effected.

A control assembly (not shown) can be provided on the gimbal 70 of theimaging device 400. The control assembly can be provided on the carryingplatform 72 which carries the imaging element 80. The control assemblycan comprise a measuring part for detecting or obtaining statusinformation associated with the imaging element 80. The statusinformation can comprise a velocity, a direction, an attitude, agravity, an acceleration, a position and/or a linear velocity and/oracceleration, a direction or an inclination angle. In some embodiments,the measuring part can comprise an inertial measurement unit (IMU). TheIMU can comprise one or more of a gyroscope, a velocity sensor, anaccelerometer, a magnetometer and the like. The control assembly cancomprise a controller configured to calculate an attitude informationassociated with the imaging element 80 based upon a status informationobtained by the measuring part. For example, the detected angle and/orlinear acceleration of the imaging element 80 can be used to calculatean attitude information of the imaging element 80 about a pitch axis, aroll axis and a yaw axis of the gimbal 70. The controller can output oneor more motor signals based upon the calculated attitude information ofthe imaging element 80. The gimbal 70 can comprise a motor assembly. Themotor assembly can directly drive the gimbal 70 based upon the one ormore motor signals to effect a rotation of the imaging element 80 aboutat least one of the pitch axis, the roll axis or the yaw axis of thegimbal 70, such that the imaging element 80 can be stabilized, and aquality of an image of an imaged object obtained by the imaging element80 can be improved.

With the transmission mechanism, the follow focus, the follow focusactuator and the imaging device of the disclosure, the adaptor and theoutput member can be engaged with each other through a relative movementin an axial direction. The engagement can limit a relative rotationbetween the adaptor and the output member. The transmission mechanismcan comprise a locking member rotatably provided on the output member.The locking member can pass through the output member along an axialdirection of the output member. An operating portion provided on thelocking member can be operated to connect the locking member to ordisconnect the locking member from the adaptor, thereby a convenientattachment and/or detachment of the transmission mechanism is effected.

It will be appreciated that, numerous variations and substitutions willoccur to those skilled in the art without departing from the scope ofthe disclosure. Those variations and substitutions made in accordancewith the spirit of the disclosure are within the scope of the presentdisclosure.

What is claimed is:
 1. A transmission mechanism comprising: an outputmember; and a worm wheel shaft configured to be connected to a powerdevice to transmit a power of the power device to the output member;wherein the worm wheel shaft and the output member are engaged with eachother through a relative movement along an axial direction, and anengagement between the worm wheel shaft and the output member limits arelative rotation between the worm wheel shaft and the output member. 2.The transmission mechanism of claim 1, further comprising: a lockingmember rotatably provided at the output member and passing through theoutput member along an axial direction of the output member; wherein thelocking member is operable to connect the locking member with the wormwheel shaft or disconnect locking member from the worm wheel shaft, anda relative movement between the worm wheel shaft and the output memberis limited when the locking member is connected with the worm wheelshaft.
 3. The transmission mechanism of claim 2, wherein the worm wheelshaft comprises an engaging portion, the output member comprises aholding portion, and the engaging portion and the holding portion areconfigured to abut against each other to bring the transmissionmechanism into an assembled state or to release from each other to bringthe transmission mechanism into a disassembled state.
 4. Thetransmission mechanism of claim 3, wherein the output member comprises:a holding member configured to abut against the worm wheel shaft tobring the transmission mechanism into the assembled state or to releasefrom the worm wheel shaft to bring the transmission mechanism into thedisassembled state; and an output gear connected to the holding member,the output member being configured to output the power to a load throughthe output gear.
 5. The transmission mechanism of claim 4, wherein theholding portion is formed on the holding member.
 6. The transmissionmechanism of claim 4, wherein: the engaging portion comprises aplurality of protruding blocks and a plurality of slots each formedbetween two adjacent ones of the protruding blocks; the holding portioncomprises a plurality of protrusions corresponding to the slots; and theprotrusions are configured to engage into the corresponding slots tocause the engaging portion to abut against the holding portion or todisengage from the corresponding slots to cause the engaging portion torelease from the holding portion.
 7. The transmission mechanism of claim6, wherein the worm wheel shaft comprises a transmission shaft, theengaging portion is provided at an end of the transmission shaft, andthe plurality of protruding blocks are arranged along a circumference ofan end face of the transmission shaft.
 8. The transmission mechanism ofclaim 7, wherein: the engaging portion is a first engaging portion; andthe worm wheel shaft further includes a second engaging portion providedat another end of the transmission shaft.
 9. The transmission mechanismof claim 7, wherein the locking member passes through the output gearand the holding member and is configured to be threadedly connected tothe worm wheel shaft to abut the holding member against the worm wheelshaft or to be disconnected from the worm wheel shaft to release theholding member from the worm wheel.
 10. The transmission mechanism ofclaim 9, wherein the locking member comprises a connecting rodconfigured to be threadedly connected to the transmission shaft to causethe holding member to abut against the worm wheel shaft or to bedisconnected from the transmission shaft to cause the holding member torelease from the worm wheel shaft.
 11. The transmission mechanism ofclaim 10, wherein: the transmission shaft includes an accommodating holeand a collar extending from a position at a middle of an inner wall ofthe accommodating hole; and the worm wheel shaft is threadedly connectedto or disconnected from the connecting rod through the collar.
 12. Thetransmission mechanism of claim 11, wherein a thread is formed on asurface of the collar facing a central axis of the transmission shaft.13. The transmission mechanism of claim 9, wherein: the output gearincludes a through hole and a groove in communication with the throughhole; the holding member is mounted within the groove and includes a viahole; and the locking member is configured to pass through the throughhole and the via hole to protrude from the holding member.
 14. Thetransmission mechanism of claim 13, wherein the plurality of protrusionsare arranged along a circumference of the via hole and spaced apart fromeach other.
 15. The transmission mechanism of claim 13, wherein: theholding member includes a guide hole; and a rib is fixed at a bottomsurface of the groove facing the holding member, the rib beingconfigured to be inserted into the guide hole to guide a connectionbetween the output gear and the holding member.
 16. The transmissionmechanism of claim 4, wherein the output gear comprises a meshingportion, the output gear being configured to drive the load to rotatethrough the meshing portion.
 17. A follow focus actuator comprising: acasing; a power device; and a transmission mechanism connected to thecasing and configured to transmit a power of the power device, thetransmission mechanism comprising: an output member; and a worm wheelshaft connected to the power device to transmit the power of the powerdevice to the output member; wherein the worm wheel shaft and the outputmember are engaged with each other through a relative movement along anaxial direction, and an engagement between the worm wheel shaft and theoutput member limits a relative rotation between the worm wheel shaftand the output member.
 18. The follow focus actuator of claim 17,wherein: the transmission mechanism further comprises a locking memberrotatably provided at the output member and passing through the outputmember along an axial direction of the output member; and the lockingmember is operable to connect the locking member with the worm wheelshaft or disconnect locking member from the worm wheel shaft, and arelative movement between the worm wheel shaft and the output member islimited when the locking member is connected with the worm wheel shaft.19. An imaging device comprising: a gimbal; an imaging element providedat the gimbal; and a follow focus actuator provided at the gimbal andcomprising: a casing; a power device; and a transmission mechanismconnected to the casing and configured to transmit a power of the powerdevice, the transmission mechanism comprising: an output member; and aworm wheel shaft connected to the power device to transmit the power ofthe power device to the output member; wherein the worm wheel shaft andthe output member are engaged with each other through a relativemovement along an axial direction, and an engagement between the wormwheel shaft and the output member limits a relative rotation between theworm wheel shaft and the output member.
 20. The imaging device of claim19, wherein: the transmission mechanism further comprises a lockingmember rotatably provided at the output member and passing through theoutput member along an axial direction of the output member; and thelocking member is operable to connect the locking member with the wormwheel shaft or disconnect locking member from the worm wheel shaft, anda relative movement between the worm wheel shaft and the output memberis limited when the locking member is connected with the worm wheelshaft.